It’s more than 12,000 years in the future, and humanity’s children among the stars are a collective of engineered species divided into the Amaranthine Firmament, ruled by the exceptionally long-lived but fading Amaranthine, and the Prism Investiture of lesser, shorter-lived races at its fringes. The Amaranthine were created by a process that rendered humans effectively immortal, but still vulnerable to accident or injury; the eldest among them are more than 10,000 years old, but at that point they begin to lose their minds, and live out their days in sanctuaries with the other insane elder members of their race. Given this tendency, it’s a little odd that their form of government is selecting the eldest among them to rule, but politics and logic rarely go hand in hand in the present, so there’s no particular reason why they should in the future. Their current Emperor is seemingly walking the path to insanity now, and another, Aaron the Long-Life, has risen to oust him with the claim to be older still. There’s just something not quite right about Aaron, from his appearance in the dreams of other Amaranthine to the nature of his shadow…

Against this backdrop, we follow three primary POVs: Lycaste, one of the giantlike Melius dwelling on the Old World (Earth), who lives an isolated existence in one of its remotest Provinces until the wider world comes knocking on his door; Sotiris, an aged and well-respected Amaranthine being courted by Aaron and his followers, and with a journey to make in memory of his sister; and Corphuso, a Vulgar inventor whose creation, the Soul Engine, could change the nature of mortality and warfare, and vastly alter the balance of power in the galaxy.

Definitely the most developed of these POVs is Lycaste’s, and it’s also the most compelling. When the book first opens, the reader is tossed into a confusing tumult of names, species, places, and events that don’t really mean anything; there’s very little in the way of context at this stage and no sign that things will slow down to let you orientate yourself. It’s when the narrative switches to Lycaste that you get a chance to breathe and look around, because he doesn’t really know all that much more than the reader. His life in the Tenth Province has been a quiet one, and when he’s forced out of it and into contact with the wider world, it’s just as disorientating an experience for him too. Sometimes Lycaste is a frustrating character to share headspace with, because he’s socially graceless and has a discouragingly proprietary attitude towards the woman he loves, but rarely for this type of character, it works well, as not only are we not pushed to view him as anything else, but it’s made quite clear in his interactions with others that he isn’t neurotypical and that they are viewing events in quite a different light from our view through his eyes. I thought the author did a good job capturing his differences in perception and how frustrating an experience that can be from both sides.

Nonetheless, the initially opaque world-building that gives the other story threads their steep learning curve does gradually unfold before the reader in a way that, by the end of the book, makes it feel as intimate and familiar as a well-fitting glove. I suspect that the level of trust in the author required to get through the first quarter of the book may lose some readers, but it’s a trust that I found to be rewarded, as the end result was to build one of the few extremely advanced societies I’ve read about that felt lived-in and authentic.

The extremely layered world-building is balanced out by the relative simplicity of plot at its heart. The majority of Lycaste’s story is a bildungsroman, albeit one in a more creative and nuanced setting than most, and it takes the lion’s share of the page count. Sotiris is the most interesting as a person, but his path in this book is fairly clear from the outset, and the most compelling aspects of his story are setup for the next book. While he is the most minor of the three primary POVs, it’s Corphuso’s story that requires the most attention to detail from the reader, because there are political shenanigans that take careful reading to appreciate. Not unlike Sotiris, however, his destination is unsurprising, but it’s the route he takes to get there that fascinates.

Toner’s descriptive prose is quite lovely, rendering the environments of these exotic worlds in lush detail without getting bogged down in minutiae. It’s more matter-of-fact than a Kay or McKillip work, so those with a dislike for poetic ramblings won’t get lost in the prose, but for a debut author it is notably accomplished.

I have only one substantial criticism, which is that I believe the level of trust required to get through the total lack of context in the beginning of the book is going to alienate a lot of readers, and I think that that could have been addressed without substantially altering the story with a bit of restructuring, perhaps opening with Lycaste and gradually expanding from there once some trust has been established. I got through that section because I finish books regardless for review, and I’m glad I did since my persistence was so richly paid off, but I’ve already had to encourage one friend who was (quite fairly) discouraged by the difficulty of following the initial events to persist. It’s not unfair for a book to require a certain level of faith that things will come to make sense when it starts in medias res, but The Promise of the Child asks for more of it than most.

But with that caution in mind, I otherwise unreservedly recommend this to the patient space opera fan. This is a rich and creative debut, with a baroque and fantastical feel to it, and I think Tom Toner could be a talent to watch out for.